The American gave his mom, a former WTA star, props after his win on Saturday night in Delray Beach.
Kyle Edmund, a 2018 Australian Open semifinalist, won't be making the trip to Melbourne.
The 19-year-old American star announced the news in the comments of an Instagram post.
Kirsten Flipkens suffered an ankle injury and was forced to retire when she tripped over advertising signage in Abu Dhabi
World No. 2 wields a weapon in his quest for first AO title since 2009.
World No. 1 to play first tournament in 11 months in AO tune-up.
The Ukrainian tested positive for mesterolone in a sample that was provided last November.
